1. Field of the Invention
The present invention relates to an ink storing type writing instrument using a refill, and more particularly, to a writing instrument of the above type having a fibrous writing tip such as, for example, a felt tip.
2. Description of the Related Art
In the field of writing instruments, there is a recent trend toward frequent use of an ink storing type pen having a writing tip made of a fibrous material such as, for example, felt, synthetic fibers or animal fur. The body of such writing instrument comprises a pen barrel made of a synthetic resin accommodating therein a wadding which is impregnated with ink, and a writing tip 3 firmly fitted in and secured to a through-hole provided in the front end of the pen barrel, the rear end of the writing tip being immersed in the wadding. The pen barrel has at its rear end a tail plug fitted therein for preventing leakage of the ink, and at its front end a removable cap for covering the writing tip. Such type of writing instrument enables a writing with a relatively wide writing width due to uniform permeation of the ink from the wadding to capillary gaps defined within the writing tip.
The writing instrument having a fibrous writing tip consumes a larger amount of ink due to a relatively wide writing width as described above. As a consequence, its writing distance is significantly shorter than that of the writing instruments having a metallic writing tip or ball-point writing tip. For drawing a 5 mm-wide straight line, for example, a normal size writing instrument of this type presents a writing distance of approximately 100 m to 140 m at most. Nevertheless, the pen barrel and the writing tip must be designed to satisfactorily withstand a writing distance more than 1000 m, in order to meet a required level of mechanical strength. Accordingly, the disposal of an entire writing instrument only for the reason of consumption of ink is a waste of materials from a viewpoint of effective utilization of resources.